1. Field of the Invention
The present invention relates generally to communication systems, and in particular, to a service apparatus and method for public mobile communication network, and private wire and mobile communication network.
2. Description of the Related Art
Mobile communication systems in general are designed and implemented for a single public mobile communication network or a single private mobile communication network only. Therefore, a subscriber who registered with each mobile communication network was able to get the service only within the network he or she registered.
The following shows a public mobile communication network and the private mobile communication network being enabled within each network only. The public mobile communication network includes a plurality of mobile switching centers (MSC), a plurality of base station controllers (BSC), a plurality of base station transceiver subsystems (BTS), and mobile stations. The private mobile communication network includes a private mobile system mounted with a mobile interface, and mobile stations. The public mobile communication network and the private mobile communication network are connected to public switch telephone network (PSTN). In such a configuration, the mobile stations that are registered to the public mobile communication network can get the service over the public mobile communication network only, and similarly, the mobile stations that are registered to the private mobile communication network can get the service over the private mobile communication network only.
Therefore, such a system is somewhat inconvenient for mobile station subscribers because once the subscribers get out of the network they registered, they cannot get the mobile communication service at all. That is, if mobile stations that are currently being used are registered to the private mobile communication network, they are not accessible to the public mobile communication network, and public mobile network service is not available to the subscribers. Similarly, if mobile stations that are currently being used are registered to the public mobile communication network, they are not accessible to the private mobile communication network, so the subscribers cannot get the private mobile communication network service. In another case, despite that a subscriber is registered to both, i.e., the public mobile communication network and the private mobile communication network, when he or she wishes to access from one particular network to the other, he or she has to change the mobile station's mode. More specifically, when a mobile terminal using the public mobile communication network needs to access the private mobile communication network, the access is possible only when the mobile station's mode is changed to the private mobile communication network usage mode. Similarly, when a mobile terminal using the private mobile communication network needs to access the public mobile communication network, the access is successfully made only when the mobile station's mode is changed to the public mobile communication network usage mode.